# include <iostream>
using namespace std;

void swap(int& a,int& b){
    int t=a;
    a=b;
    b=t;
}

int main(){
int x=5,y=10;
cout<<"x= "<<x<<", y= "<<y<<endl;
swap(x,y);
cout<<"x= "<<x<<", y= "<<y<<endl;
return 0;
}